Such a method is known from EP 0 289 813 B1. The method described there already operates very safely.
For areas such as an upper or a lower end area of a shaft or an accessible intermediate destination however, in view of safety considerations, particularly strict regulations apply with regard to speed monitoring. The speed monitoring must be undertaken here in two independent ways. A first type of monitoring implemented in conveyor installations is by comparing an actual speed value, which has been determined for example by a pulse counter mounted on a drive shaft of a motor, with a speed value calculated in the automation system. Another is for detection elements, such as magnets or end position switches or light barriers, to be used along the conveyor path for additional path and speed monitoring of conveyor means. A pulse issued by a detection element notifies the automation system about the instantaneous location of the conveyor means. A maximum permitted speed value belonging to this location is compared to the actual speed value. A second type of protection is thus implemented in the automation system.